When you are keying in a program PIP will grumble at you if:-
* You have not entered any numbers (red keys) after an instruction other than and you try to enter another instruction.
* The memory is full. You can only enter 48 separate commands in one program.
* You have pressed when the memory is already empty.
* You have pressed 0 after a command that needs a number.
* You have pressed a number before entering a command.
* You have tried to enter too many numbers after a command. You can enter up to three numbers after , , , and .The largest number you can use here is 999. You can enter up to two numbers after which means that the largest number of repeats that you can use at once is 99. You can only enter one note after each .
* You have tried to nest 's more than three deep.
* You have tried to put in an without a matching .
* You have left PIP on for more than two minutes without pressing any buttons.
When you press or , PIP will grumble at you if:-
* You have entered a command without an amount.
* You have entered a without a matching .
* PIP has been stopped from running by running into something.
* You pressed a key to stop PIP.
PIP will sing when:-
* You turn PIP on.
* Your program has run without any mistakes in it.